Some health professionals claim that they are essential to make up for the fact that most of us aren't eating enough fruit and veg.

Others say that supplement pills do nothing and you're wasting your money.

So, what's the truth?

Let's start with some facts.

48% of British adults regularly take a multi-vitamin or dietary supplement, and this translates to a lot of money.

By 2025, sales of vitamins and supplements are expected to reach a record £559 million, an increase of 13% from 2020.

Now, the general consensus in the scientific community is that vitamin supplements don't actually do very much unless there is already a nutritional deficiency.

And this is where it starts to get interesting because it means that it matters who is taking the supplements.

In 2018, Cochrane, a hugely respected organization that reviews medical research, published a review of all the available evidence on the use of Omega 3 supplements during pregnancy.

They found that supplementing with Omega 3s during pregnancy reduced the risk of having a premature baby⏤one born before 37 weeks⏤by 11% and reduced the risk of having a very premature baby⏤one born before 34 weeks⏤by 42%.

And for that reason, they recommend that women pregnant with one baby, rather than twins, for example, be advised to supplement with 500 to 1,000 milligrams of Omega 3s every day from the 12th week of pregnancy.

Pregnant women should also take a folic acid supplement to support the development of their baby's nervous system.

One surprising place where nutritional supplements seem to make a big difference is prison.

A series of studies stretching back nearly 30 years has found the same remarkably consistent finding.

Providing prisoners with vitamins and mineral supplements reduces violence by a third compared to placebo.

Scientists are still trying to work out exactly why this is.

One possibility is that, for example, we know that the chemicals that your brain uses to send messages⏤called neurotransmitters, like serotonin⏤are made from nutrients.

So, not having enough nutrients is like a chef not having all the right ingredients for a recipe.

This research has the potential to dramatically improve the conditions in prisons and other similar settings.

Not only would prisoners feel calmer and more able to manage their emotions, but it would make prisons safer for staff.

Another unexpected but consistent finding is that vitamins, in particular, B vitamins, can help you to manage stress.

And a group of researchers in New Zealand showed that supplementing people with vitamins and minerals following the acute stress of an earthquake reduced their risk of later development of post-traumatic stress disorder, or PTSD, compared to those who didn't take the nutrients.

And in later life, some studies have shown that supplementation with B vitamins alongside Omega 3s can slow down the rate of something called neurodegeneration.

Now, this is when brain cells stop functioning properly and they even die.

And these kinds of illnesses are currently the leading cause of death here in the UK, and there's no cure.

So, anything that can help to protect the brains earlier in life will be really important for everybody's health.

But, of course, we need to wait for more research before we know exactly who would benefit from what kind of treatment.

So, this all sounds great, but there are a couple of very important downsides to supplements for some groups of people.

And one⏤now infamous⏤research study highlights this risk.

Testing the theory that antioxidants could protect against cancer, individuals with a high risk of lung cancer were given high doses of beta-carotene and retinol, two forms of vitamin A.

However, the study had to be halted early because the supplement group developed more aggressive cancers than the placebo group, and they had a higher death rate even years after the end of the trial.

It's thought that the high doses of antioxidants interfered with the immune system, allowing the cancer to grow unchecked.

So, if you are undergoing any kind of medical treatment, it's really essential that you discuss any plans for supplementation with your care team.

And, on top of that, some vitamins such as A, D, E, and K at high doses over a long time can lead to toxicity.

So, supplements might be beneficial for some people at greater risk of nutritional deficiencies or where there is an additional nutrient demand.

That might be families on low incomes, pregnant women, people with diabetes, or anyone on a restricted diet or one that involves cutting out whole food groups such as vegans, vegetarians, or people with coeliac disease.

But it seems that most of us would just be better off trying to take steps to improve our overall diets.

And I know that can sound daunting because we can have an all-or-nothing approach to diets and think that we have to throw everything out of the cupboards and start from scratch.

But that kind of approach can be too much too soon, leaving you feeling overwhelmed and discouraged.

And when I'm working with people one-to-one, I generally suggest that they start just by adding one piece of fruit or vegetables to their normal meals.

So, that might mean slicing a banana over your cereal, adding a handful of spinach to your lunchtime sandwich, or half a can of lentils to your pasta sauce.

Over time, this approach can improve your diet quality without much effort.